In their last tweet, Bitcoin Core references a page on Github, which contains a request to include the SegWit2x code in the current protocol in order to make both versions compatible.

Previously, Segwit2x developers confirmed that it plans to implement hardwork on the block 494,784. This code, although includes support for Segregated Witness activated last week, will be incompatible with the current version of Bitcoin Core.

Last week later developers SegWit2x in their mailing list said that version 1.14.5 ready to use. At the same time, the Bitcoin Core team believes that the development of SegWit2x conducted too hastily and without sufficient user support and developer community as a whole. The greatest criticism is the refusal to include in the SegWit2x code protection from replay attacks.

Previously, the developers of Segwit2x stressed that the increase in the size of the block to 2Mb, has agreed by the participants during NYA. Agreement provided Segwit implementation, and then the block size will increased to 2Mb. Working group Segwit2x insists that the ecosystem participants need to update their software in any case.